Example embodiments relate to phase-change memory devices and methods of manufacturing the same.
As a design rule of a phase-change memory device is reduced, misalignments between a phase-change material layer and an upper electrode or between the upper electrode and a bit line may occur, so that the phase-change material layer may be exposed and vaporized during fabrication. In a phase-change memory device with a conventional cell structure including an upper electrode between the phase-change material layer and the bit line, as the phase-change memory device becomes more highly integrated, misalignment between the upper electrode and the phase-change material layer may occur more frequently.
As the cell size of the phase-change memory device decreases, it may be desirable to use a phase-change memory device cell structure without an upper electrode. However, when an etch stop layer is formed on the phase-change material layer without an upper electrode during an etching process for forming a bit line, the etch stop layer may not be removed completely.